Connectors that are used to align two optical fibers are commonly referred to as optical connectors. The vast majority optical connectors are of the “physical contact (PC)” type, and are referred to as PC optical connectors. In a PC optical connector that is used to connect to fibers the two fibers are physically touching under pressure. For single mode fibers, the glass optical core of the fiber has to be aligned extremely accurately to ensure a low loss connection. The core of the fiber is generally between 6 and 100 microns, with 9-10 micron core fiber being almost universally used for telecommunications. This small core means that a scratch or dust on a fiber will cause the light to be greatly attenuated and for the communication link to be lost.
Another type of optical connector is the “expanded beam (EB)” optical connector. An EB optical connector eliminates (or reduces) the effect of dust contamination or scratches by using a pair of lenses 101, 102 to focus the light between the two fibers 104,105, as illustrated in FIG. 1. Expanded beam connectors commonly use ball lenses in a metal block with steel alignment pins to ensure the light is focused back into the fiber without significant loss. These implementations rely on the accuracy of the machining of this block, the pins, the lens and the fiber ferrule in order to provide a reasonably low optical insertion loss.
What is desired is an improved EB optical connector.